What Is Contact Tracing and Why Is It Crucial to Reopening California?

People sit in San Francisco's Alamo Square Park during the coronavirus pandemic on May 3. (Rich Fury / Getty Images)

Thousands of public employees and volunteers are training to become contact tracers for the state of California, beginning a crucial step in the statewide fight to stop the spread of coronavirus and reopen businesses for cash-strapped citizens. But what exactly is contact tracing and why is it critical to easing the state out of current restrictions?

Contact tracers must identify individuals who test positive for COVID-19 and help them self-isolate to prevent further spread. They then gather a list of all of the people who came into close contact with the infected individual, communicate with that list of contacts to warn them they were potentially exposed and provide self-isolation information or testing services. They must also monitor the symptoms of each person in that list of contacts until their test results are returned or they pass the 14-day incubation period.

Traditional contact tracing is a laborious but crucial method to help manage the spread of a viral epidemic as the nation awaits a successful vaccine or prophylactic treatment. According to a white paper from the Johns Hopkins Center for Health Security, an infected individual is estimated to infect an average of two to three other people. “This means that if 1 person spreads the virus to 3 others, that first positive case can turn into more than 59,000 cases in 10 rounds of infections,” the paper said.

As the state begins to slowly reopen and people begin to relax on following physical distancing guidelines, a newly infected individual’s contacts will grow — and make contact tracing even more difficult. And until there are more (and better) COVID-19 tests available in the supply chain, there is the risk that asymptomatic individuals can slip through the cracks of traditional contact tracing and trigger more chains of infection, Robert Siegel, a Stanford microbiology and immunology professor, told TheWrap.

Thus, contact tracing and testing are just “a piece of the puzzle” in managing the pandemic, Siegel said. “Testing and contact tracing does not take the place, for instance, of making sure you avoid infection and washing your hands and wearing a mask,” he said.

The first goal, Siegel said, is to decrease the probability of transmission down to less than one person per case. “Once that happens, then the number of cases begins to fall. And what you want to do is … bring that number of cases down to zero,” he said. “Once that happens, it’s still critically important to have in place excellent contact tracing because, just like in China, there’s always the possibility that someone from the outside can reintroduce the virus.”

“On average, people become symptomatic in about five to six days after exposure and we can find the virus, on average, two days before they become symptomatic. So you might have three days, on average, to get them,” John Swartzberg, an infectious diseases and vaccinology specialist at the UC Berkeley-UCSF Joint Medical Program, told TheWrap. “The longer it’s going to take me to identify these people and to get them in quarantine, the greater the chance these people are going to have to spread the disease.”

Contact tracers and state agencies must also determine if an infected individual has a safe place to self-isolate and the resources to sustain themselves and, if not, connect them with public services to help. Also, some individuals can’t be contacted through the phone or email, meaning that contact tracers may have to go and knock on doors or engage in other methods.

The process also has privacy implications, especially when technology like cellphone apps are used to facilitate the process. The state of Washington is requiring all restaurants that resume dine-in service to keep a log of all patrons — with names, phone numbers and emails — for at least 30 days to aid tracers seeking potential contacts for any newly infected people.

Some companies, like Apple and Google, are developing apps that take advantage of smartphone Bluetooth technology to help determine whether a user has been in close contact with someone who has tested positive for COVID-19. Many of these apps have precautionary measures in place to protect people’s identities, but there still remains concern that apps — some of which use smartphones’ GPS data — could be used to track citizens’ movements or otherwise allow the government to collect sensitive data on users. And that is a catch-22 when it comes to public health. “The more anonymity you preserve, the less public health can use that data to control the pandemic,” Swartzberg said.

In the meantime, a statewide program led by the University of California, San Francisco, is training 10,000 civil servants to be contact tracers and relies on “low level” technology like phone calls, texts, emails and management software to help the contact tracers stay organized, George Rutherford, the head of UCSF’s Division of Infectious Disease and Global Epidemiology, said. “This is really shoe-leather stuff. You’ve got to interview people, you’ve got to be able to talk to them and you’ve got to be able to convince them that they should, that they need to participate,” he said.

But given the sheer number of new infections in the state, a more efficient and longer-term system will necessitate some combination of these detective-like contact tracers and smartphone apps, health experts told TheWrap. Once a sustainable system is worked out, health experts also emphasized the need to maintain contact tracing resources beyond this pandemic.

“We’re sort of reinventing what we should have been doing all along,” Swartzberg said. “It would have been really nice if we started this [pandemic already] with a robust contact tracing program for other communicable diseases and then just ramped that up.”

As with any early-stage program, there are bound to be bumps along the way as California attempts to expand its contact tracing capabilities. But through those bumps, the state hopes to emerge with a stronger public health system than before.

“Ultimately, it will work. Ultimately, we’ll figure out all these things and it will work,” Swartzberg said. “But it’s going to be a slog.”

It's not just your old high school and college buddies that are using stay-at-home quarantines during the coronavirus pandemic as an excuse to reconnect with you over Zoom. The casts and teams behind over a dozen beloved shows or films have reunited remotely in recent weeks just to pass the time. Many of the stars are doing conversations for charity, while others are staging full remote episodes or special performances just to perk up a fan's day. In case you missed them earlier, here are all the reunions that took place since the shutdowns began, and we'll add more as they inevitably take place.

Josh Gad/YouTube

"The Goonies"

On April 27, Josh Gad hosted a reunion with almost the entire full cast of the '80s cult classic "The Goonies," including Sean Astin, Josh Brolin, Martha Plimpton, Kerri Green, Jeff Cohen, Ke Huy Qyan, Corey Feldman, Joe Pantoliano and Robert Davi. Gad also spoke with writer Chris Columbus and even got the 90-year-old director Richard Donner to join the call, though not without some technical difficulties first. The cast asked each other questions about what reactions they get from fans and even re-enacted a handful of scenes from the film.

Warner Bros.

"Hamilton"

After John Krasinski had a wave of support for the first episode his makeshift YouTube series "Some Good News" in which he chatted with his co-star on "The Office" Steve Carell, he then surprised a fan of "Mary Poppins Returns" who said her favorite musical was "Hamilton" and that she missed out on a performance of the show because of the coronavirus. Lin-Manuel Miranda then brought together the cast of the original Broadway production, including Daveed Diggs, Leslie Odom Jr, Okieriete Onaodowan, Phillipa Soo, Christopher Jackson, Anthony Ramos, Jasmine Cephas Jones, Renée Elise Goldsberry and Jonathan Groff, to sing the show's opening number.

Photo by Theo Wargo/WireImage

"Friday Night Lights"

The cast of the TV series "Friday Night Lights" reunited for Global Citizen's "Together at Home," with the cast specifically gathering to virtually watch the pilot episode of the series. Adrianne Palicki, Scott Porter, Derek Phillips, Aimee Teegarden, Gaius Charles and Brad Leland took part, though stars Kyle Chandler and Connie Britton couldn't attend. On the Zoom call, the cast also recalled how competitive actor Taylor Kitsch was playing flag football.

NBC

"Melrose Place"

For the first time since 2012, Heather Locklear and the cast of "Melrose Place" reunited as part of the YouTube series "Stars in the House" to support The Actors Fund. Josie Bissett, Thomas Calabro, Marcia Cross, Laura Leighton, Heather Locklear, Doug Savant, Grant Show, Andrew Shue, Courtney Thorne-Smith and Daphne Zuniga all took part to reminisce about the soapy Fox drama.

Fox

"Contagion"

While not strictly a reunion, the cast of Steven Soderbergh's pandemic outbreak drama "Contagion" banded together to help provide PSAs with advice about social distancing, hand washing and more. Matt Damon, Kate Winslet, Laurence Fishburne and Jennifer Ehle were among the first set to record the informational videos, which were made in partnership with Columbia University’s Mailman School of Public Health, the same school that also consulted on "Contagion" the film.

Warner Bros.

"That Thing You Do!"

The members of the fictional band The Wonders (or The Oneders) from Tom Hanks' film "That Thing You Do!" reunited for the first time since the film's release in 1996. Band members Tom Everett Scott, Johnathon Schaech, Ethan Embry and Steve Zahn all joined up with co-star Liv Tyler in honor of Adam Schlesinger. Schlesinger wrote the Oscar-nominated title song from the film and shortly before the reunion died of COVID-19.

Twentieth Century Fox

"High School Musical"

The cast of "High School Musical" didn't stream their Zoom reunion call, which from Instagram photos shared by the cast included director Kenny Ortega along with Truman Alfaro, Vanessa Hudgens, Paul Becker, Corbin Bleu, Monique Coleman, Lucas Grabeel and Ashley Tisdale. They did however participate in Disney's "Family Singalong" show, with star Zac Efron delivering a special message in lieu of being able to perform.

Disney Channel

"Parks and Recreation"

The cast of "Parks and Recreation" performed an entire virtual episode as part of a standalone, scripted special on NBC inspired by social distancing. Amy Poehler, Rashida Jones, Aziz Ansari, Nick Offerman, Aubrey Plaza, Chris Pratt, Adam Scott, Rob Lowe, Jim O'Heir and Retta all reprised their roles from the sitcom series to raise money for Feeding America's COVID-19 Response Fund. The episode aired Thursday, April 30 on NBC.

NBC

"Full House"

The cast of "Full House," including John Stamos, Bob Saget, Dave Coulier, Candace Cameron Bure, Jodie Sweetin, Andrea Barber and creator Jeff Franklin, all imagined a parody intro to their famous '90s sitcom for a brief TikTok video they called "Full Quarantine." It showed Saget sanitizing a Swiffer and Coulier fishing a slice of pizza out of a pond and ended with the caption, "unlike 'Full House,' this will all go away."

Photo by ABC Photo Archives/ABC via Getty Images

"My So-Called Life"

The cast of the sitcom "My So-Called Life" held a private Zoom reunion call that included Wilson Cruz, Claire Danes, Bess Armstrong, Devon Odessa, Tom Irwin, Mary Kay Place, Devon Gummersall and A.J. Langer. The series creator Winnie Holzman and her husband Paul Dooley also joined the call, though Jared Leto was not present.

ABC

"Victorious"

The stars of the Nickelodeon TV series "Victorious," featuring Victoria Justice and Ariana Grande, were already meant to gather around this time for the 10th anniversary of the series, but instead did so virtually. Elizabeth Gillies, Leon Thomas III, Matt Bennett, Avan Jogia, Daniella Monet and Eric Lange, as well as the show’s creator Dan Schneider, all participated in the call along with Grande and Justice.

Nickelodeon

"The Maze Runner"

"The Maze Runner" actress Kaya Scodelario shared a screenshot on Instagram of her Zoom call with her co-stars from the YA adventure trilogy, including Dylan O’Brien, Will Poulter, Ki Hong Lee, Dexter Draden and Thomas Brodie-Sangster. "We survived the Glade, the Scorch & whatever the third one was about. We got this," Scodelario said in the post.

20th Century Studios

"Jessie"

The cast of the Disney Channel series "Jessie" dedicated their gathering to Cameron Boyce, who passed away last year at age 20. Star Debby Ryan appeared on the episode of "Stars at Home" along with Peyton List, Skai Jackson, Karan Brar and Kevin Chamberlin.

Disney Channel

"Taxi"

Another classic TV franchise with an unexpected reunion, the cast of the sitcom "Taxi" got together for an hour-long chat for "Stars in the House," including Danny DeVito, Judd Hirsch, Carol Kane, Christopher Lloyd and Marilu Henner.

NBC

"Chuck"

EW rallied the cast and crew of the NBC comedy series "Chuck" to not only reminisce about the show but also perform a table read of a fan-favorite episode from, the ninth episode of Season 3, "Chuck Versus the Beard." Zachary Levi, Yvonne Strahovski, Adam Baldwin, Joshua Gomez, Sarah Lancaster, Ryan McPartlin, Vik Sahay, Scott Krinsky and Mark Christopher Lawrence all took part in the reunion, as did "Chuck" co-creators Josh Schwartz and Chris Fedak.

Will Smith reunited with his cast members from "The Fresh Prince" as part of the two-part season finale for his Snapchat series "Will at Home." He was joined by Alfonso Ribeiro, DJ Jazzy Jeff, Tatyana Ali, Karyn Parsons, Daphne Maxwell Reid and Joseph Marcell. Smith and "The Fresh Prince" cast also paid tribute to the actor who played Uncle Phil, James Avery. Smith recalled that the reason his character's name on the show is Will Smith is because Ribeiro told him that people would be calling him by his character's name for the rest of his life.

Chris Cuffaio/NBCU Photo Bank

"Back to the Future"

For the second episode of his "Reunited Apart" show, Josh Gad virtually reunited Michael J. Fox, Christopher Lloyd and Lea Thompson to talk what Gad called a "perfect" movie in "Back to the Future." Lloyd said the film was at one point supposed to be called "Spaceman From Pluto."

Universal

"Community"

Nearly the entire cast of NBC's sitcom "Community" will reunite on May 18 to do a live table read of the Season 5 episode "Cooperative Polygraphy." Series stars Joel McHale, Gillian Jacobs, Danny Pudi, Yvette Nicole Brown, Alison Brie, Jim Rash, Ken Jeong and Donald Glover, who left the series after season 5, will join creator Dan Harmon to read the Season 5 episode titled “Cooperative Polygraphy.” The special will stream on the “Community” YouTube page on May 18 at 2 p.m. PT and will also include a fan Q&A.

NBC

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Stars from “Chuck,” “The Nanny,” “Frasier,” “Taxi” and more have taken part in table reads and Q&A specials

It's not just your old high school and college buddies that are using stay-at-home quarantines during the coronavirus pandemic as an excuse to reconnect with you over Zoom. The casts and teams behind over a dozen beloved shows or films have reunited remotely in recent weeks just to pass the time. Many of the stars are doing conversations for charity, while others are staging full remote episodes or special performances just to perk up a fan's day. In case you missed them earlier, here are all the reunions that took place since the shutdowns began, and we'll add more as they inevitably take place.